I had to use my superchips to pull the code through the OBD-II port. Doing the key dance shows nothing.

Bring it to an autozone or advance and tell them you got that warning message and want to check for any codes. They should do it for free then you can look up what code they give you and the FSM has troubleshooting guides for all of the codes.

I just started getting the service 4wd on my 05, no codes will show. It will only come on when it has sat overnight or sat long enough to cool down. When I start it after it is warmed up it won't come on again until it has cooled down again.